Poly(silyl silane) homo and copolymers

Abstract

Poly(silyl silanes) have been prepared. They have high photosensitivity and excellent resistance to oxygen-reactive ion etching processes. They are useful as photodepolymerizable photoresists, barrier layers, etc.

What is claimed is: 
     
       1. A method of photopatterning an image onto a substrate coated with a photoresist comprising irradiating the coated substrate with actinic radiation forming a pattern of said image on the substrate, said photoresist being a positively-acting, substantially non-crosslinked linear poly(silyl silane) having at least ten recurring units. 
     
     
       2. A method of claim 1, whereby the portions of said polymer on which the radiation impinges are photovolatilized, whereby said substrate becomes uncoated in the pattern of said image. 
     
     
       3. A method of claim 1, wherein said substrate is one suitable for use in a microelectronic device. 
     
     
       4. A method of claim 1, further comprising treating the thus-exposed surface areas of said substrate by oxygen reactive ion etching. 
     
     
       5. In a method of forming an image in a substrate comprising exposing the substrate in coated form to oxygen-reactive ion etching wherein the coating on the substrate is at least ternary and comprises a planarizing layer, a barrier layer and a photoresist layer, the improvement wherein said ternary portion is replaced by a binary portion comprising a planarizing layer and a layer of a photoresist which is a positively acting, substantially not-crosslinked, linear poly(silyl silane) having at least 10 recurring units which serves the function of both said barrier and photoresist layers. 
     
     
       6. A coated substrate suitable for use in oxygen-reactive ion etching wherein said coating comprises a planarizing layer and a layer of a photoresist which is a positively acting, substantially not-crosslinked, linear poly(silyl silane) having at least 10 recurring units which is effective as both an oxygen-reactive ion etch resistant barrier layer and a photoresist layer. 
     
     
       7. A method of photopatterning an image onto a substrate coated with a photoresist which is a positively acting, substantially not-crosslinked, linear polysilane having a main chain of at least 10 catenated Si atoms and pendant side groups, wherein at least one group is a silyl group, comprising irradiating the coated substrate with actinic radiation forming a pattern of said image on the substrate. 
     
     
       8. A process of claim 1, wherein said polymer is a poly(silyl silane) of the formula ##STR6## wherein each of A, B, C, D, E and F independently is organosilyl, poly(organosilyl), organo or H, at least one of A, B, C, D, E and F being organosilyl or poly(organosilyl).   
     
     
       9. A process of claim 8, wherein said polymer is a homopolymer. 
     
     
       10. A process of claim 8, wherein said polymer is a copolymer. 
     
     
       11. A process of claim 8, wherein the polymer is essentially oligomer free. 
     
     
       12. A process of claim 8, wherein none of A, B, C, D, E and F is H. 
     
     
       13. A process of claim 12, wherein the organo groups are C 1-15  -alkyl, C 2-7  -alkylene, C 3-15  cycloalkyl, C 6-14  -aryl, C 7-20  -aralkyl or C 7-20  -alkaryl and those in the side chain silyl groups can also be organosilyl or poly(organosilyl) and n is at least 30. 
     
     
       14. A process of claim 8, wherein all of A, B, C, D, E and F are organosilyl or poly(organosilyl). 
     
     
       15. A process of claim 8, wherein only ne of A, B, C, D, E and F is silyl or poly(organosilyl). 
     
     
       16. A process of claim 8, wherein at least two of A, C, and E are silyl or poly(organosilyl). 
     
     
       17. A process of claim 8, wherein the organo portions are aliphatic or aromatic groups whereby said polymer is resistive to oxygen-reactive ion etching. 
     
     
       18. A process of claim 8, wherein the organo groups are C 1-15  -alkyl, C 2-7  -alkylene, C 3-15  -cycloalkyl, C 6-14  -aryl, C 7-20  -aralkyl or C 7-20  -alkaryl and those in the side chain silyl groups can also be organosilyl or poly(organosilyl) and n is at least 30, and the polymer is essentially oligomer free. 
     
     
       19. A process of claim 13, wherein the organo portions are methyl, ethyl, n- or i-propyl, t-butyl, cyclohexyl, phenyl, phenyl-C 1-3  -alkyl or C 1-3  -alkylphenyl. 
     
     
       20. A process of claim 13, wherein the silyl groups are trimethylsilyl groups. 
     
     
       21. A process of claim 13, wherein said organo groups are substituted by C 1-8  -alkyl, C 1-8  -alkoxy, C 6-10  -aryl, mono- or di(C 1-6  -alkyl)-amino, C 2-8  -alkanoyl or a corresponding ketal, amino, hydroxy or C 2-8  -alkanoyloxy. 
     
     
       22. A process of claim 19, wherein only one side group of the polymer's repeating unit is silyl. 
     
     
       23. A process of claim 21, wherein only one side group of the polymer's repeating unit is silyl. 
     
     
       24. A process of claim 8, wherein said copoly(silyl silane) is of the formula ##STR7## wherein B and D are methyl and A and C are cyclohexyl/trimethylsilyl, t-butyl/trimethylsilyl, i-propyl/trimethylsilyl or n-propyl/trimethylsilyl and n is at least 30. 
     
     
       25. A process of claim 8, wherein said copoly(silylsilane) is of the formula ##STR8## wherein B and D are methyl and A and C are cyclohexyl/triphenylsilyl, t-butyl/triphenylsilyl, i-propyl/triphenylsilyl or n-propyl/triphenylsilyl and n is at least 30. 
     
     
       26. A process of claim 8, wherein said copoly(silylsilane) is of the formula ##STR9## wherein B and D are methyl and A and C are cyclohexyl/triethylsilyl, t-butyl/triethylsilyl, i-propyl/triethylsilyl or n-propyl/triethylsilyl and n is at least 30. 
     
     
       27. A process of claim 1, wherein the poly(silylsilane) is in isolated form. 
     
     
       28. A process of claim 1, wherein the poly(silylsilane) is essentially oligomer-free. 
     
     
       29. A process of claim 1, wherein the poly(silylsilane) is substantially non-crystalline. 
     
     
       30. A process of claim 1, wherein the poly(silylsilane) is soluble in non-polar solvents. 
     
     
       31. A process of claim 7, wherein the poly(silylsilane) is essentially oligomer free. 
     
     
       32. A process of claim 1, wherein n is at least 500 and n is the number of recurring units, and said polymer is essentially oligomer free. 
     
     
       33. A process of claim 1, wherein n is at least 1,000 and n is the number of recurring units, and said polymer is essentially oligomer free. 
     
     
       34. A process of claim 1, wherein the poly(silyl silane) is a solid, linear polymer of the formula ##STR10## wherein p1 each of A, B, C, D, E and F independently is organosilyl, poly(organosilyl), organo or H, at least one of A, B, C, D, E and F being organosilyl or poly(oranosilyl),   and n is at least 10, and said polymer is essentially oligomer free.   
     
     
       35. A process of claim 1, wherein the polymer is a solid linear polysilane having a main chain of at least 10 catenated silicon Si atoms and pendant side groups, wherein at least one side group is a silyl group. 
     
     
       36. A process of claim 1, wherein said polymer is a solid, linear poly(silyl silane) having at least 10 recurring units. 
     
     
       37. A process of claim 36, wherein said solid, linear poly(silyl silane) is of the formula ##STR11## wherein each of A, B, C, D, E and F independently is organosilyl, poly(organosilyl), organo or H, at least one of A, B, C, D, E and F being organosilyl or poly(organosilyl),   and n is at least 10.